[gp712] add include <stdbool.h> to resolve build issues (#3804)

examples/platforms/gp712/alarm_qorvo.h

@@ -36,6 +36,7 @@
 #define ALARM_QORVO_H_
 
 #include <stdint.h>
+#include <stdbool.h>
 #include <sys/time.h>
 #include <unistd.h>
 

examples/platforms/gp712/platform_qorvo.h

@@ -39,6 +39,7 @@
 #include <openthread-core-config.h>
 
 #include <stdint.h>
+#include <stdbool.h>
 
 typedef void     (*qorvoPlatPollFunction_t)(uint8_t);
 typedef uint8_t  (*qorvoPlatGotoSleepCheckCallback_t) (void);